The present invention relates to scanners and plotters in general, and more particularly, to a laser beam scanner/plotter optical system.
Laser beam scanners and photoplotters are well known in the graphics industry. Such scanner and plotters can be classified in at least two categories: drum and flatbed scanners. As the size of the scanned original and the plotted film input increases, there is a concomittant increase in the requirements for physical and optical accuracy. These accuracies can be achieved to some measure, albeit often at the expense of physical size for the optics and the moving bed in a flatbed scanner.
It is accordingly a general object of the invention to provide an improved scanner/plotter.
It is a specific object of the present invention to provide a scanner/plotter optical system having a relatively small physical profile.
It is another object of the invention to provide a scanner optical system that utilizes unsharp masking.
It is still another object of the invention to provide a scanner that compensates for unstraight scan lines.
It is a further object of the invention to provide an encoder for scanner/plotter optical systems that utilizes equal conjugates.
It is a still further object of the invention to provide an encoder for scanner/plotter optical systems in which encoder information is derived from a stationary image of the main galvonometer mirror.
It is a feature of the invention that the scanner/plotter optical system can be constructed from conventional optical elements.
It is another feature of the invention that the optical elements of the scanner/plotter optical system are arranged in a physically compact configuration.
It is a further feature of the invention that the encoder grating can be placed optically in the same plane as the scan/plotting plane.